(a) Field of the Invention
The present invention relates to the field of electrical wiring installations. More particularly the present invention relates to the field of spacing means used in conjunction with electrical wiring boxes and screw fastening means.
(b) Background Art
When installing indoor electrical switch and outlet plates on the walls, electrical wiring boxes are often placed inside the walls behind the electrical plates. Electrical wiring boxes are usually rectangular shaped metal, plastic or fiberglass box frames with various openings and holes for mounting with screws and running electrical wires. The dividing walls in modern homes and offices typically have a hard central portion and a surface portion. The hard central portion is the major part of a wall, which stands the stress, and is what is ordinarily called the “wall”. The surface portion, often called “dry wall”, is the exposed part that is later placed as a covering onto the center portion of the wall for decoration and other purposes, and is usually made of tile or similar light material. In the following discussion if not otherwise specified, the word “wall” is used to specify the central portion of a wall, and the word “dry wall” is used to specify the surface portion of a wall.
In the practice of indoor electrical installations, within an open wall an electrical wiring box is installed, and upon closing of the wall with dry wall, a square shaped chamber is cut out from the dry wall. The size of chamber is usually greater than the size of the electrical wiring box to which the chamber pertains. The electrical box often has receiving arms and mounting arms with screw holes. Mounting arms can be fastened to an edge of the chamber by using nails or fastening screws to tightly mount the electrical box to the wall. After the electrical box is installed into the wall, dry wall is placed over the wall, and an opening is cut out at the position of the electrical box for installing electrical wall plates such as electrical switch plates or power outlet plates. Typically, these electrical wall plates have mounting arms with screw holes. If there is no dry wall, mounting arms of these electrical wall plates may be directly brought into contact with receiving arms of the electrical box and fastened by screws. However, due to the thickness of the drywall and the resulting gap between the electrical wall plate mounting arms and the electrical box receiving arms, it can be difficult to mount these electrical wall plates when there is dry wall covering the wall.
Historically, electricians either wrap a lot of wire around the screws or, alternatively, use other shims such as rings of washers to provide means with a certain thickness to fill the gap between the electrical wall plate mounting arms and the electrical box receiving arms caused by the presence of the dry wall. These conventional approaches are both inconvenient and unstable.
In recognition of the inconvenience of the above-identified electrician “work-arounds”, a plastic foldable spacer to be used in conjunction with electrical boxes has further been developed in the prior art. The plastic foldable spacer known in the prior art is an elongated strip of a certain thickness comprising a series of foldable sections that may be folded into a corrugated spacer which is designed to have a precise thickness based on the number of sections, each section having a defined and consistent thickness when folded. Each of the sections of the foldable strip has a screw hole at the center, resulting in a corrugated spacer having a central screw hole allowing a screw to go through to fasten the mounting arms of the electrical wall plate to the receiving arms of the electrical box. The strip is typically formed of plastic and recent improvements in the design have yielded strips comprising a chain of adjoined segments, each adjoining segment having the ability to snap to the counterpart segment to which it is adjoined, and a central slot cut in to each segment in lieu of a central hole, thus allowing the folded spacer to be slid on to an existing screw binding an electrical wall plate mounting arm to an electrical box receiving arm.
While the use of the above-described plastic foldable spacer is a marked improvement over the inconvenient and unstable conventional approaches previously discussed, a significant shortcoming remains in that the segments of these folding spacers do not stack flush due to the combination of the material resistance in folding the apparatus and the insufficient length of the hinges adjoining the segments. Because the segments do not stack flush upon one another the precision of a desired thickness in using the spacer apparatus is compromised and a user can never be sure of the precise thickness needed or used to space the gap between the mounting arms of the electrical wall plate and the receiving arms of the electrical box.
A further shortcoming in the foldable spacers known in the prior art is that the segments of the folding spacers are all rectangular prisms in shape, meaning that each segment contains at least eight (8) right angle corners that have a tendency to catch on clothing and tool pouches and pockets when a user is attempting to grab a spacer for use on a project. Being that the segment corners are an unneeded feature of the device and, in fact, constitute a nuisance in the use of the foldable spacers known in the prior art, the extra material required to form the corners is a material waste that can be quite expensive in the context of mass production of the foldable spacer.
Accordingly, there is a need in the prior art for a convenient and stable means of spacing the dry wall gap between the mounting arms of an electrical wall plate and the receiving arms of an electrical box, the means to be capable of precise and incremental augmentation of the spacer thickness on an as needed basis by a user. By way of example, the specific contemplated need in the prior art is for a user to be able to precisely insert a ⅛″ spacer, a ¼″ spacer, a ⅜″ spacer, etc. using a single spacer device.
It is therefore an object of the present invention to provide an elongated strip which may be torn or cut to any desired thickness comprising a series of foldable sections, so that the elongated strip can be folded into a corrugated spacer which has a precise thickness as determined by folding on top of each other multiple sections, each having a precise thickness, and in turn can be used to fill the gap between two corresponding mounting arms of the electrical wiring devices.
It is a further object of the present invention to provide a foldable strip with a series of sections, each having a screw slot extending from a common edge when the strip is folded to the center of each section, so that the resultant corrugated spacer will have a central screw slot and when used to fill the gap, is enabled to slip around an existing screw already anchored between the two corresponding mounting arms of the electrical wiring devices.
It is a still further object of the present invention to provide a foldable strip with a series of sections, each section being designed and constructed in such a way to use a minimal amount of material and further avoid the existence of corners on sections, thus allowing for easier handling and cost-savings in mass production of the overall device.
It is also an object of the present invention to provide a foldable strip made of thin sheets of plastic material, so that it will provide the desired flexibility with enough strength and insulation to be used with electricity.
Further novel features and other objects of the present invention will become apparent from the following detailed description and discussion, taken in conjunction with the drawings.